The goal of this project is to understand the major elements involved in transcriptional regulation of the Wilms' tumor WT1 gene. Experiments are designed to identify and clone novel trans-acting proteins (enhancers, silencer, promoter elements) involved in the modulation of WT1 expression. The genetic loci for these transacting regulatory proteins will be determined since mutation at these loci may be important in the development of Wilms' tumor.